Available Bytes Counter Definition is Incorrect in Perfmon

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Workstation version 4.0

SUMMARY

The counter definition in Performance Monitor for the object Memory and counter Available Bytes incorrectly states that:

Available Bytes displays the size of the virtual memory currently on the
Zeroed, Free, and Standby lists. Zeroed and Free memory is ready for
use, with Zeroed memory cleared to zeros. Standby memory is memory
removed from a process's Working Set but still available. Notice that
this is an instantaneous count, not an average over the time interval.

Available Bytes is the amount of physical memory available to processes
running on the computer, in bytes. It is calculated by summing space on
the Zeroed, Free, and Standby memory lists. Free memory is ready for
use; Zeroed memory is pages of memory filled with zeros to prevent later
processes from seeing data used by a previous process. Standby memory is
memory removed from a process's working set (its physical memory) on
route to disk, but is still available to be recalled.

MORE INFORMATION

Available Bytes is correctly defined as Physical Memory in the following documents:

Windows NT Workstation 4.0 Resource Kit: Part III, Chapter 12, Page 400

Available Bytes:
Description: How much memory is left for processes to allocate? This is
an instantaneous count, not an average.

The counter "Memory Available Bytes" displays the amount of free
physical memory. If this counter stays consistently below 4 MB, paging
is occurring and performance is less than optimal.

Additional query words: help mem perf-mon

Keywords : kbbug4.00
Version : WinNT:4.0
Platform : winnt
Issue type : kbbug kbinfo